Dual hub assembly for reels

ABSTRACT

An assembly for mounting in an opening in a panel to drive two reels reversibly for driving a magnetic recording tape reversibly comprises: a spool-shaped housing attachable to the rear of the panel; two coaxial shafts extending through the housing and the opening in the panel; two coaxial hubs on the front ends of the two shafts, respectively; outer circumferential elastomeric rings on the two hubs respectively; screw means incorporated in the two hubs, respectively, to compress the corresponding elastomeric rings for radial bulging of the rings into binding engagement with the two corresponding reels; two motors on the rear end of the housing to drive the two coaxial shafts respectively; two electrically actuated brakes adapted when deenergized to retard the two coaxial shafts respectively; and two oppositely oriented one-way clutches connecting the two brakes to the respective shafts so that when the power supply fails with resultant deenergization of the two motors and the two brakes, the brake for whichever reel is functioning as a supply reel retards the supply reel with the other takeup reel freewheeling.

United States Patent 2,466,974 4/1949 Stupakoffet al 24 Claims, 10 Drawing Figs.

U.S. Cl 242/ 193, 242/72 Int. Cl G03b 1/04, Gllb 15/32; B65h 75/18 Field of Search 242/ l 93, 68.1, 68.2, 72; 269/48.I; 279/2 References Cited UNITED STATES PATENTS Primary Examiner-Leonard D. Christian Attorney-Smyth, Roston and Pavitt ABSTRACT: An assembly for mounting in an opening in a panel to drive two reels reversibly for driving a magnetic recording tape reversibly comprises: a spool-shaped housing attachable to the rear of the panel; two coaxial shafts extending through the housing and the opening in the panel; two coaxial hubs on the front ends of the two shafts, respectively; outer circumferential elastomeric rings on the two hubs respectively; screw means incorporated in the two hubs, respectively, to compress the corresponding elastomeric rings for radial bulging of the rings into binding engagement with the two corresponding reels; two motors on the rear end of the housing to drive the two coaxial shafts respectively; two electrically actuated brakes adapted when deenergized to retard the two coaxial shafts respectively; and two oppositely oriented one-way clutches connecting the two brakes to the respective shafts so that when the power supply fails with resultant deenergization of the two motors and the two brakes, the brake for whichever reel is functioning as a supply reel retards the supply reel with the other takeup reel freewheeling.

PATENTEU FEB 9L9?! SHEET 1 BF. 3

PATENTEU FEB 9 1971 same or 3 mm R PATENTEUFEB 9mm I 3561,1699

sum 3 or 3 ITI'ORMEW DUAL nun ASSEMBLY FOR REELS BACKGROUND OF THE INVENTION At the present state of the art relating to coaxial hub assemblies for driving coaxial reels there are certain long existing needs for improvement and one of these needs is to provide a simplified coaxial reel construction for the sake of economy. Coaxial reels are, of course, mounted on a pair of coaxial shafts and to make such an assembly compact it is common to employ a pair of coaxial motors. A coaxial motor arrangement, however, is expensive and complicated. A further need, therefore, is for a satisfactory dual motor arrangement that is not coaxial.

Another disadvantage of prior art dual reel assemblies is that the constructions are expensive because they are so largely made up of especially fabricated parts. The need in this respect is for a dual reel construction that is made in large part of relatively inexpensive commercially available components.

A further disadvantage of many of the previous dual hub assemblies, and especially the more complicated assemblies, is that it is difficult to dismantle the assemblies for servicing or repair of parts. The need is for an assembly that can be removed bodily from the panel on which it is mounted and I that can be quickly and conveniently separated into its component parts.

In addition to the above needs for structural improvement there is a pressing need for a new method of releasably holding a reel on a hub. One prior art method of engaging a reel on a hub is to employ cam actuated jaws, for example as shown in the Cohen et al. US. Pat. No. 3,124,319. A cam actuated jaw mechanism is necessarily complicated and expensive. Cam actuated metal jaws, moreover, generate excessive engagement forces that too often damage the reels.

Another prior art method of engaging a reel on a hub is to force an O-ring up a conical surface to expand the O-rigng into pressure contact with an inner circumferential rim of the reel. Such an arrangement is disclosed, for example, in the Craig US. Pat. No. 2,992,787 and also in the Martin et al. US. Pat. No. 3,322,365. One disadvantage of such an arrangement is that the O-ring is repeatedly stretched and tends to be weakened by repeated stretching. A more serious disadvantage is that since the O-ring is forced against an inner circumferential edge of the reel, the O-ring issubjected to concentrated stress that not only permanently deforms the O-ring but also causes the -O-ring to'stretch in the course of time. Deterioration of the O-ring makes it difficult to force a reel onto the hub and makes it necessary to lubricate the O-ring repeatedly.

Another problem to be met is the problem of manipulating the inner hub of a pair of coaxial hubs for the purpose of engaging a reel therewith. Since the two coaxial hubs must be compact and closely spaced, the inner hub is not readily accessible for manipulation of its mechanism and especially so when accessibility is reduced by the presence of a reel on the inner hub.

A still further problem to be met with reference to improvement of prior art devices is the problem of preventing damage to a tape by snarling of the tape in the event that the power fails. What is required in this regard is a fail-safe mechanism that becomes effective automatically when a power failure occurs.

The invention is directed to the above mentioned needs and problems.

SUMMARY OF THE lNVENTION The need for a simplified and economical construction for a dual reel assembly is met by a number of improvements. One improvement is the concept of journaling the two coaxial shafts of a dual hub assembly in a tubular housing that is releasably attached to the back face of a panel with the two coaxial shafts extending forwardly of the housing through a circular opening of the panel to carry a pair of coaxial hubs forwardly of the panel. Two motors to drive the coaxial shafts and two brakes for the coaxial shafts are mounted on radial wings at the inner end of the housing, the two shafts being driven by timing belts. In such an arrangement the housing may be detached by screws accessible from the front of the panel and then the whole assembly may be withdrawn rearwardly with the two hubs passing through the circular opening in the panel.

A feature of the invention is the further concept of employing a pack of components on the rear end ofthe assembly with thrust bearings separating the components and employing a retaining means across the rear end of the assembly tokeep the pack compressed, the retainer means being releasably anchored to the tubular housing. Simply releasing the retainer means from the tubular housing makes it possible to separate the components of the pack for withdrawal of the two coaxial shafts forward through the tubular housing. Such an arrangement makes access to the various moving parts exceedingly simple to expedite servicing of the assembly.

The need for an improved method of releasably engaging a reel on each of the two coaxial hubs is met by making each hub in two separate sections which together form a circumferential groove around the hub and which are movable axially relative to each other for the purpose of contracting and expanding the width of the groove, An elastomericring of substantial axial and radial dimension is seated in the groove for axial compression by axial contraction of the groove, the axial compression of the elastomeric ring causing it to bulge radially outwardly into frictional engagement with a reel on the hub.

in such an arrangement the elastomeric ring is not stretched since its inside diameter remains. constant. Neither is the elastomeric ring subjected to concentrated stress because the compressive force is distributed over the whole of the two end faces of the ring with the consequence that the ring is subjected to only relatively low unit stress. A further special ad vantage of employing an elastomeric ring in this manner is that its radially outward force is a yielding force and is distributed over a relatively large inner circumferential area of the reel.

/ The yieldability of the force is a safeguard against damaging the reel and the extensive area of mutual contact between the reel and the elastomeric ring results in subjecting the reel to only low unit stress.

The mechanism for axially compressing the elastomeric rings of thetwo hubs comprises simple screw means in engage-' ment with one section of each hub for cooperation therewith to exert thrust against the other section of the hub. In the preferred embodiment of the invention a suitable thrust bear-' ing is interposed between the screw means and them movable sectionof the hub to transmit the screw force to the movable section with minimum friction.

The problem of manipulating the rear hub to engage a rear reel is solved by two expedients. One expedient is releasable means to connect the screw means of the rear hub to the forward hub so that the forward hub may be employed as manual means to rotate the screw means. The second expedient is simple means to interlock the rear reel and the rear hub to permit the rear reel to be employed as manual means to hold the rear hub against rotation while the forward hub is being employed for manual rotation of the screw means of the rear hub.

As will be explained, a feature of the invention is that the mechanism to connect the forward hub to the rear screw means may in effect be cocked" at any position of rotation of the forward hub relative to the rear screw means. With the connecting mechanism cocked it is merely necessary to rotate the forward hub relative to the rear screw means until the connecting mechanism snaps into engagement with the rear screw means.

A further feature of the invention is the concept of providing a convenient knob at the outer end of the coaxial reel assembly which is movable between a first position and a second position for two different purposes. At its first position the knob is operatively connected to the screw means of the forward hub for expansion and contraction of the elastomeric ring of the forward hub. At its second position the knob is operatively connected to the above described connecting mechanism to cock the mechanism.

The problem of preventing damaging snarling of the tape in the event of power failure is solved by a fail-safe arrangement comprising two electrically actuated brakes and two associated one-way clutches for connecting the brakes to the respective coaxial shafts. Each of the brakes is in its released state when it is electrically energized, each brake being applied by spring means when it is deenergized. The two oneway clutches are oppositely oriented to make the two brakes effective selectively, each brake being effective only when the corresponding reel is operating as a supply reel.

The selective action of the two brakes may be understood when it is considered that when the direction of the tape is reversed, the functions of the two reels are reversed, the takeup reel being converted into a supply reel and the supply reel being converted into a takeup reel. The reversal of the direction of rotation of the two coaxial shafts automatically makes the brake effective for whichever reel is employed as a supply reel, the other reel simply freewheeling in the event of power failure.

The various features and advantages of the invention may be understood from the following detailed description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, which are to be regarded as merely illustratlve:

FIG. I is a rear perspective view of the presently preferred embodiment of the coaxial hub assembly with the hub assembly removed from the panel on which it is usually mounted;

FIG. 2 is a longitudinal section of the coaxial reel assembly as taken along the line 2-2 of FIG. I in the direction of the arrows;

FIG. 3 is a fragmentary radial section taken as indicated by the line 3-3 of FIG. 2 to show how two small radial screws cooperate to prevent accidental disassembly of a screw means of a hub;

FIG. 4 is a longitudinal sectional view of the two hubs showing how the mechanism to releasably connect the outer hub to the screw means of the inner hub is cocked for subsequent snap action;

FIG. 5 is a view similar to FIG. 4 showing the connecting mechanism snapped into engagement with the screw means of the inner hub;

FIG. 6 is a fragmentary transverse section taken as indicated by the line 6-6 of FIG. 5 showing how longitudinal pins of the connecting mechanism engage the screw means of the inner hub;

FIG. 7 is a view partly in side elevation and partly in section showing one of the brakes and the associated one-way clutch;

FIG. 8 is a transverse section taken as indicated by the line 8-8 of F IG. 5;

FIG. 9 is a perspective exploded view of the knob at the outer end of the assembly and the cooperating means for latching the knob at its inner position; and

FIG. 10 is a transverse section along the line 10-10 of FIG. 4 showing how the knob is latched at its inner position.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION General Arrangement Referring to FIGS. 1 and 2, the hub assembly includes a tubular spool-shaped housing 10 adapted to be mounted on a panel 12 at a circular opening 14 in the panel, the assembly including a forward or outer hub, generally designated 15 and a rear coaxial hub 16, the circular opening 14 of the panel being of a diameter to clear the two hubs. The two hubs are mounted on coaxial shafts, the rear hub being mounted on the outer end of a tubular shaft 18 and the forward hub being mounted on the outer end of an axial shaft 20. The tubular shaft 18 is journaled in forward and rearward needle bearings 22 with the bearings protected by a leather dust seal 25 and a cooperating coil spring 26. In like manner the axial shaft 20 is journaled inside the tubular shaft 18 by means of forward and rearward needle bearings 28.

The rear end of the tubular shaft I8 carries a toothed pulley 30 and the rear end of the axial shaft 20 carries asimilar toothed pulley 32. In the construction shown, a thrust bearing 34 is interposed between the toothed pulley 30 and the rear end of the spool-shaped housing 10; a second thrust bearing 35 is interposed between the two toothed pulleys 30 and 32 and a third thrust bearing 36 is interposed between the toothed pulley 32 and a suitable releasable retainer means. The retainer means includes a flat washer 38 and a transverse retainer plate 40. I

As shown in FIG. I the retainer plate 40 is anchored to the spool-shaped housing 10 by means of long screws 44 with cooperating nuts thereon. With the two hubs I5 and I6 releasably mounted on the coaxial shafts 18 and 20 it is apparent that releasing the retainer plate 40 from the housing I0 permits the two coaxial shafts with the two toothed pulleys thereon to be withdrawn forward from the spool-shaped housing. Such a construction makes it a simple matter to dismantle the assembly whenever desired.

The rear end of the spool-shaped housing 10 is provided with two diametrically opposite wings 45 mounted thereon by suitable screws, one wing carrying a motor 48 and brake 50 for controlling the pulley 30, the other wing carrying a motor 52 and a brake SI (FIG. 2) similar to brake 50 for controlling the pulley 32. In the construction shown, a timing belt 55 in mesh with the pulley 30 passes around a drive pulley 56 of the motor and also passes around a toothed pulley 58 associated with the brake 50. In like manner a second timing belt 60 in mesh with the second pulley 32 passes around a drive pulley 56 of the motor 52 and around a pulley 58 associated with the corresponding brake. As best shown in FIG. 7 each of the two brakes is operatively connected to the corresponding pulley 58 by means ofa one-way clutch 62.

The two hubs are designed to mount reels of a well known type that have three equally spaced longitudinal grooves or recesses on their inner circumferential surfaces. Such grooves or recesses are designated 63 in FIG. 8.

The forward hub 15 incorporates suitable screw means which will be described in detail hereafter and which operates to releasably compress a forward elastomeric ring 62 to cause the elastomeric ring to bulge radially outwardly into releasable frictio'nal engagement with the inner circumference of a forward reel 64. In like manner, the rear hub 16 is provided with similar screw means to compress a rear elastomeric ring 65 for radially bulging the ring into frictional engagement with the inner circumference of a rear reel 66. The screw means of the forward hub 15 is operated by a forward concentric knob 68. As will be explained, the same knob 68 may be shifted axially out of engagement with the screw means of the forward hub 15 to actuate a connecting mechanism for operatively connecting the forward hub to the screw means of the rear hub. After such a connection is accomplished, the forward hub may be manually rotated to control the radial expansion and contraction of the rear elastomeric ring 65.

As shown in FIG. I, suitable means in the fonn of radially projecting pins 69 are provided on the rear hub 16 to engage inner longitudinal recesses 63 of the inner reel 66 to keep the reel from rotating relative to the rear hub whereby the reel 66 may be employed as manual means to immobilize the rear hub while the screw means of the rear hub is being operated by manual rotation of the forward hub. In the same manner, the forward hub I5 is provided with a radially projecting pin 70 to engage an inner longitudinal recess of the reel 64 to permit the reel 64to serve temporarily as manual means for immobilizing the forward hub 15 while the screw means of the forward hub is being operated by the knob 68.

The forward reel 64 backs against three radial lugs 71 of the forward hub which serve as stops for the reel. In like manner the rear reel 66 backs against stop means which comprises three radial lugs 72 but may, if desired, comprise a continuous radial flange. ln installing the rear reel 66, it is first passed over the forward hub with the three inner longitudinal recesses 63 of the reel oriented to clear the three radial stop lugs 7l of the forward hub as shown in FIG. 8. Since the radial pin 70 of the forward hub 15 would block the mounting of the rearward reel 66 when the rearward reel is oriented to clear the three stop lugs 71 of the forward hub, the radial pin 70 is retractable in response to abutment by the rearward reel.

In the construction shown (FIGS. 1 and 8) the retractable pin 70 is a headed pin that is slidingly mounted in a radial bushing 73 and is urged radially outward by a coil spring 74. HO. 8 shows the pin 70 retracted by the axially moving rearward reel 66.

To mount the two reels 64 and 66 on the two hubs l5 and 16, respectively, both of the elastomeric rings 62 and 65 are initially relaxed, i.e. radially contracted. First the inner reel 66 is passed over the forward hub 15 as above described onto the rear hub 16 into abutment with radial stop lugs 72 of the inner hub and into engagement with the radial pins 69. The knob 68 is then manipulated to cause the forward hub 15 to be operatively connected to the screw means of the inner hub 16. Since the reel 66 is engaged by the radial pins 69, it may be employed as manual means to prevent rotation of the rear hub 16 while the forward hub 15 is being manually rotated to tighten the screw means of the rear hub thereby to expand the rear elastomeric ring 65 into effective engagement with the inner reel 66. The forward reel 64 is then mounted on the forward hub 15 in abutment with three stop lugs 71 and in engagement with the retractable pin 70. With the forward reel 64 engaged by the retractable radial pin 70, the reel is employed as manual means to prevent rotation of the forward hub while the knob 68 is being manually rotated to operate the screw means of the forward hub to expand the forward elastomeric ring 62 into efiective engagement withthe reel 64.

A feature of the invention is that the elastomeric rings will engage reels of different thicknesses. The drawings show reels that are one-half inch thick but it is apparent that reels l inch thick may be mounted on the two hubs if desired.

The two brakes are normally released, i.e.' are released when the brakes are electrically energized and are applied when electrically deenergized. Consequently, when a power failure occurs both brakes are applied automatically in a failsafe manner. With the two brakes applied as a consequence of a power failure the one-way clutches make effective only the brake that is associated with whichever reel is functioning as a supply reel.

STRUCTURAL DETAILS As shown in HO. 2, the rear hub 16 is divided into two sections 16a and 16b of the same outside diameter, section 16a being of stepped configuration to permit the section 1611 to be slidingly mounted thereon with the two sections keyed together to prevent relative rotation. In the construction shown, the key means comprises at least one pin 75 carried by the section 16a which slidingly extends into a longitudinal bore 76 in the section 16b.

The hub section 16a is cut away circumferentially to cooperate with the hub section 16b to form an outer circumferential groove 80 to seat the rear elastomeric ring 65 and as may be seen in FIG. 2 there is sufficient clearance between the two sections to permit lateral contraction of the groove 80 by axial movement of the hub section 16b towards the hub section 160. Screw means in the form of a threaded bushing 82 controls the relative axial positions of the two hub sections to control the radial outward bulging of the elastomeric ring 65 for engagement with the reel 66.

The screw means 82 for the rear hub 16 threadedly telescopes into the hub section 16a and engages the hub section 16!) to drive the hub section 16h axially towards the hub section 16a. In the construction shown, the bushing 82 has a radial flange 84 which is overhung by the hub section 16h with a suitable thrust bearing 85 interposed between the flange and the hub section, the thrust bearing minimizing frictional resistance to rotation between the screw means and the hub section.

Once the rear hub 16 and its screw means 82 are assembled, it is essential to prevent inadvertent unscrewing of the screw means 82 out of screw-threaded engagement with the hub section 16a. For this purpose, as shown in FIGS. 2 and 3. the screw means or bushing 82 is provided with a radially extending headed screw 86 and the hub section 16b is provided'with a threaded radial bore 88 in which a headless set screw 90 is mounted toretractably extend into the path of rotation of the screw 86. When the hub structure is being assembled. the set screw 90 is retracted to avoid interference with rotation of the bushing 82 but once the hub is assembled, the set screw 90 is advanced inwardly to the position shown in FIG. 3 to limit the relative rotation of the bushing 82 to l80 rotation, l80 being sufficient to squeeze and relax the elastomeric ring 65.

The forward hub 15 is of the same construction, comprising a hub section 15a and a hub section 15h which are keyed together in the previously described manner by at least one pin 74. The screw means for the forward hub comprises a bushing 92 that screw-threadedly telescopes into the hub section 1511, the bushing being provided with a radial flange 94 to exert axial pressure on the hub section 15h by means of a thrust bearing 95. Here again two previously described radial screws 86 and 90 in the bushing 92 and the hub section 15, respectively, limit unscrewing rotation of the bushing 92.

Whenever desired the screw means or bushing 92 of the forward hub 15 may be manually rotated by the forward knob 68 that is journaled on a shoulder bolt 104 that is mounted concentrically on the forward end of the inner shaft 20. It is to be noted that the knob 68 is movable axially on the shoulder bolt 104 between a normal forward position shown in FIG. 2 and a rearward position shown in FIGS. 4 and 5. The knob 68 at its forward position is operatively connected to the screw means or bushing 92 of the forward hub 15 and, as will be explained, movement of the knob rearward to its second position actuates means for releasably connecting the forward hub to the screw means or bushing 82 of the rear hub.

The knob 68 is of the construction shown in FlGS. 9 and 10, the knob being formed with an inner hub 105 and two fingers 106 of arcuate cross section extending longitudinally from the hub. A narrow plate 108 is mounted on the face of the inner hub 105 by suitable screws 110 and forms two lugs 112 that extend radially from the inner hub. As shown in FIGS. 2 and 10, the screw means or bushing 92 of the forward hub 15 has an inner radial flange 114 which is formed with two diametrically opposite inner circumferential recesses 115 and as shown in FlGS. 2 and 6, the screw means or bushing 82 of the rear hub 16 is of similar construction being formed with a radially inward flange ll6 with a pair of diametrically opposite inner recesses 118 in the flange. At the normal forward position of the knob 68 the two radial lugs H2 of the inner plate 108 extend into the corresponding inner recesses 115 of the screw means or bushing 92 of the forward hub 15 so that rotation of the knob at its forward position is imparted to the bushing or screw means 92.

The means for releasably connecting the forward hub 15 to the screw means 82 of the rear hub 16 for manual operation of the screw means by the forward hub comprises a pair of diametrically opposite longitudinal pins 120 which extend through corresponding bores 122 in the rear wall of section 15a of the forward hub for releasable engagement with the above mentioned inner recesses 118 of the rearward screw means 82. The two longitudinal pins 120 slidingly extend through corresponding apertures in a thin disc 124 that is slidingly mounted on the forward end of the inner shaft 20, the pins 120 being provided with forward retaining rings 125 that limit the rearward movement of the pins relative to the disc. A

suitable coil spring 126 surrounds each longitudinal pin 120 under compression between the disc 124 and a fixed collar 128 of the pin to continuously urge the pin rearward relative to the disc. A relatively heavy coil spring 130 surrounds the shaft 20 under compression between the disc 124 and the rear wall of the hub section 15a to continuously urge the disc towards its normal forward position shown in FIG. 2.

When the knob 68 is shifted axially rearwardly, the two longitudinal pins 120 are almost always out of register with the corresponding inner circumferential recesses 118 of the screw means 82 of the rearward hub and therefore the rearward movement of the longitudinal pins is stopped by abutment of the pins against the inner radial flange 116 of the screw means as shown in FIG. 4. Consequently, when the knob 68 is forced rearward the rearward fingers 106 of the knob force the thin disc 124 rearward in opposition to the coil spring 130 and with the pins 120 stopped in their rearward movement, the springs 126 of the pins are compressed between the disc 124 and the fixed collars 128 ofthe pins. At this time, the radial lugs 112 of the inner plate 108 of the knob 68 are shifted rearward from the inner radial flange 114 of the screw means or bushing 92 as shown in FIG. 4, but the lugs 112 of the inner plate 108 are in alignment with the recesses 115. The operator may now rotate the knob slightly to shift the lugs 1112 out of register with the recesses 115 as shown in FIG. 10 and then the manual pressure on the knob 68 may be relaxed to permit rcturn movement of the disc 124 by the coil spring 130. The return movement of the disc 124 is limited because the two fingers 106 of the knob 68 abut the forward face of the disc and forward retreat of the fingers 106 is limited by abutment of the lugs l 12 of the inner plate 108 against the rearward face of the inner radial flange 114 of the screw means 92, the parts being then in the positions indicated by FIGS. 5 and 10.

It is apparent that the two longitudinal pins 120 for releasably connecting the forward hub to the screw means of the rear hub may in efiect be cocked by simply forcing the knob 68 axially inward, rotating the knob slightly and then releasing the knob to permit the pressure of the spring 130 to force the lugs 112 into abutment with the rear face of the inner radial flange 114 of the forward bushing 92. When the pins 120 are c0cked" in this manner, the small coil springs 126 continuously urge the pins rearward against the inner radial flange 1 16 of the screw means 82 of the rear hub 16.

With the pins 120 cocked, the operator may grasp the forward hub 15 to rotate the forward hub relative to the rear hub 16 until the longitudinal pins 120 snap rearward into engagement with the inner recesses 118 of the screw means 82 of the rear hub. With the longitudinal pins 120 thus operatively connecting the forward hub to the screw means 82 of the rear hub, the forward hub may be employed as manual means for rotating the inner screw means 82. At this time, a reel 66 is on the rear hub and is employed as manual means to prevent rotation of the rear hub when the forward hub is rotated manually to operate the screw means of the rear hub.

After the rear elastomeric ring 65 is radially expanded in engagement with the rear reel 66 by rotation of the rear screw means 82 by the forward hub, the knob 68 may be rotated relative to the forward hub until the lugs 112 of the inner plate 108 again register with the inner recesses 115 of the forward screw means 92 whereupon the spring 130 acting on the thin disc 124 and the thin disc, in turn, acting on the ends of the inner fingers 106 of the knob 68 return the knob to its normal forward position where the lugs 112 of the inner plate 108 engage the inner recesses 115 of the forward screw means. Thus, the knob 68 is returned to its normal forward position in operative engagement with the forward screw means 92. The forward reel 64 may then be telescoped over the forward hub 15 against the radial stop lugs 71 and then the knob 68 may be rotated clockwise to actuate the forward screw means 92 for bulging the forward elastomeric ring 62 into engagement with the inner circumference of the forward reel 64.

To remove the two reels from the hub assembly, the knob 68 is first rotated counterclockwise to relax the forward elastomeric ring 62 to release the forward reel 64 for removal from the forward hub. For complete relaxation of the forward elastomeric ring 62, it may be necessary to grasp the forward reel 64 to prevent rotation of the forward hub during the completion of the unscrewing action of the forward screw means 92.

With the forward reel 64 removed, the knob 68 is moved axially inward, rotated slightly and then released to cock" the two longitudinal pins 120. The operator then grasps the rear reel 66 to immobilize the rear hub and manually rotates the forward hub until the longitudinal pins snap into engagement with the inner recesses 118 of the rear screw means 82. The operator then employs the forward hub as manual means to loosen the rear screw means 82 while continuing to grasp the rear reel 66 to immobilize the rear hub. With the rear elastomeric ring 65 relaxed. the rear reel may be removed by aligning the inner recesses 63 of the reel with the radial stop lugs 71 of the forward hub. As the reel 66 is moved forward past the forward hub, the reel cams the spring-pressed pin 70 of the forward hub radially inward out of the way.

Our description in specific detail of the presently preferred embodiment of the invention will suggest various changes, substitutions and other departures from our disclosure.

We claim:

1. In an apparatus for driving two reels to control a ribbon of flexible material with one reel functioning as a takeup reel and the other reel functioning as a supply reel for moving the ribbon in one direction and vice versa, the combination of:

two hub structures to mount the two reels respectively; two corresponding motors to drive the two hub structures respectively in one respect for use of one reel as a takeup reel and use of the other reel as a supply reel and in the opposite respect for use of the said one reel as a supply reel and said other reel as the takeup reel; two corresponding brakes; two corresponding one-way clutches operatively connecting the two hub structures respectively to the two brakes;

each of said two oneway clutches being oriented to permit freewheeling of the corresponding reel when the corresponding reel is rotated in the direction to serve as a takeup reel;

said two brakes being electrically actuated brakes and being released when energized and applied when deenerigized; and

whereby with the two motors and the two brakes energized by a common EMF source, failure of the source with consequent deenergization of the two motors makes effective the brake of whichever hub structure is rotating its reel in the direction to serve as a supply reel.

2. A combination as set forth in claim 1 in which the braking force of each of the two brakes is applied by spring means when the brake is deenergized and in which the spring means is adjustable to vary the braking force.

3. In an apparatus for rotatably mounting two closely spaced coaxial reels, the combination of:

closely spaced forward and rearward axially aligned hub structures to mount a forward reel and a rearward reel respectively;

- two outer circumferential elastomeric rings on the two hub structures respectively;

screw means on the two hub structures respectively operable to compress the corresponding rings axially without changing the inside diameter of the rings thereby to cause the two rings to bulge radially outward into engagement with the corresponding reels;

manual means having a first normal position at which it is operatively connected to the screw means of the forward hub structure; and

said manual means being movable to a second position to releasably interconnect the forward hub structure and the screw means of the rearward hub structure thereby to permit the forward hub structure to serve as means to operate the screw means of the rearward hub structure,

I said manual means at its second position being operatively disconnected from the screw means of the forward hub structure.

4. ln an apparatus for rotatably mounting two closely spaced coaxial reels, the combination of:

closely spaced forward and rearward axially aligned hub structures to mount a forward reel and a rearward reel respectively;

two outer circumferential elastomeric rings on the two hub structures respectively;

screw means on the two hub structures respectively to compress the corresponding rings axially to expand the rings into engagement with the corresponding reels;

shoulder means on the rearward one of the two hub structures;

connecting means disposed on the forward one of the two hub structures and movable between first and second positions and disposed in the first position out of register with the rearward hub structure and operative in the second position to engage the shoulder means of the rearward hub structure;

manual means to operate the screw means of the forward hub structure;

said screw means of the rearward hub structure having a forward end wall that blocks movement of said connecting means to its second position when the connecting means is out of register with said shoulder means;

manually operable cocking means to place said connecting means under spring pressure to urge the connecting means to its second position; and

whereby with the connecting means out of register with the shoulder means, the cocking means may be operated to place the connecting means under spring pressure and the relative rotation may then be created between the forward hub structure and the screw means of the second hub structure until the connection means is registered with the shoulder means to permit the connecting means to snap into engagement with the shoulder means.

5. A combination as set forthin claim 4 in which said shoulder means comprises a plurality of longitudinal bores in the forward end of the screw means of the rearward hub struc ture and said connecting means comprises a corresponding plurality of pins dimensioned to enter said bores.

6. In an apparatus for rotatably mounting two closely spaced coaxial reels, the combination of:

closely spaced forward and rearward axially aligned hub structures to mount a forward and a rearward reel respectively;

said forward hub structure having a rear transverse wall with a first plurality of bores longitudinally therethrough;

two outer circumferential elastomeric rings on the two hub structures respectively;

screw means on the two hub structures respectively to compress the corresponding elastomeric rings axially to expand the elastomeric rings into engagement with the cor responding reels; and

said screw means of the rearward hub structure having a second plurality of bores longitudinally thereof corresponding to the first plurality of bores to register therewith at a given rotary position ofthe forward hub structure relative to the screw means of the rearward hub structure; I

a plurality of pins mounted respectively in said first plurality of bores, each of said pins having a first flange means on its rearward end and second flange means intermediate between its two ends;

an axially movable transverse means in the forward hub structure having a plurality of portions respectively adjacent said pin between the first and second flange means thereof;

a plurality of coil springs respectively embracing said pins between said transverse means and said second flange means of the pins; 1

said transverse means having a normal forward position against said first flange means of the pins to keep the pins retracted from the second plurality ofholes and having an alternate rearward position comprcssingsaid coil springs against the second flange means of the pins to urge the pins into the second plurality of holes thereby to operatively connect the forward hub structure to the screw means of the rearward hub structure for operation of the screw means by the forward hub structure;

manually rotatable means having a normal forward position for engagement with the screw means of the forward hub structure for rotation thereof and being movable to a rearward position against said transverse means to force the transverse means to its second position; and

whereby when the forward hub structure is out of said given relative rotary position, said manually rotatable means may be moved to its second position to cause said transverse means to compress said coil springs and then the forward hub structure may be rotated to said given relative rotary position to cause the coil springs to snap the pins into the second plurality of bores.

7. A combination as set forth in claim 6 in which said second flange means of the plurality of pins are positioned to cooperate with said transverse wall of the forward hub structure to limit the movement of the pins into the second plurality of holes.

8. A combination as set forth in claim 6 which includes means to releasably latch said manually rotatable means at its second position.

9. A combination as set forth in claim 6 which includes means to releasably latch said forward manually rotatable means at its second position in response to relatively small rotation of the manually rotatable means at its second position.

10. In an assembly for mounting at an opening in a panel to drive two'reels on the forward side of the panel, the combination of:

a housing for attachment to the panel in a position extend-' ing rearwardly of the panel in alignment with said opening;

a pair of coaxial shafts comprising an inner axial shaft and an outer tubular shaft encompassed by the housing and extending both forwardly and rearwardly from the housing;

a forward hub structure on the forward end of the axial shaft formounting and driving a forward reel;

two power means carried by the housing and operatively connected to the rear ends of said two shafts respectively to drive the two hub structures respectively; and

said two hub structures being of less diameter than said opening whereby said housing may be detached from the panel to permit the assembly to be withdrawn rearwardly from the panel with said structures passing rearwardly through said opening in the panel.

ll. A combination as set forth in claim 10 which includes:

retaining means extending across the rear end of said assembly;

thrust bearing means effective between the rear ends of the two shafts and said housing;

means to releasably anchor the retaining means to the housing thereby to cooperate with said thrust bearing means to maintain the two shafts in their assembled positions relative to the housing; and

whereby the retaining means may be released and said hub assemblies may be removed from the front ends of the two shafts to permit the two shafts to be withdrawn forward from the housing.

12. In apparatus for rotatably mounting two spaced reels,

the combination of:

a first shaft;

a second shaft coaxial with the first shaft;

a first hub mounted on the first shaft for engaging and driving a first one of the two spaced reels;

a second hub mounted on the second shaft for engaging and driving a second one of the two spaced reels;

control means having first and second positions and operative in the first position to engage the first hub for driving the first hub and operative in the second position to become disengaged from the first hub; and

means operatively coupled to the first hub and responsive to the engagement of the first hub by the control means in the first position of the control means for operating upon the second hub to lock the second hub and the second reel.

13. In the combination set forth in claim 12, means on the second hub for engaging the second reel during the action of locking the second hub and the second reel to prevent the second reel from being rotated relative to the second-hub during such locking action.

. 14. In the combination set forth in claim I2, means operatively coupled to the first hub and responsive to the operation of the control means in the second position for operating upon the first hub to lock the first hub and the first reel.

15. In the combination set forth in claim 14, means on the first hub for engaging the first reel during the action of locking the first hub and the first reel to prevent the first reel from being rotated relative to the second hub during such locking action,

16. In apparatus for rotatably mounting two spaced reels, the combination of:

a first shaft;

a second shaft coaxial with the first shaft;

a first hub mounted on the first shaft for driving a first one of the two spaced reels;

a second hub mounted on the second shaft for driving a second one of the two spaced reels;

means operatively coupling the first and second hubs for synchronously operating the first and second hubs during the action of locking of the second reel on the second hub; and

means operatively disengaging the first and second hubs for disengaging the second hub from the first hub during the action of locking the first reel on the first hub.

11. In the combination set forth in claim I6, means on the second hub for engaging the second reel, during the action of locking the second hub on the second reel, to prevent the second hub from rotating relative to the second reel during such locking action.

18. In the combination set forth in claim 17, means on the first hub for engaging the first reel, during the action of locking the first hub on the first reel, to prevent the first hub from rotating relative to the first reel during such locking action.

19. In apparatus for rotatably mounting two spaced the combination of:

a first shaft;

a second shaft coaxial with the first shaft;

a first hub mounted on the first shaft for engaging and driving a first one of the two spaced reels;

a second hub mounted on the second shaft for engaging and driving a second one of the two spaced reels; first means on the first hub and movable between first and second positions and extending to the second hub for engaging the second hub in the first position for movement of the second hub with the first hub and disposed in the second position in disengagement with the second hub;

second means on the first hub and movable between first and second positions and operative in the first position on the first hub to obtain a movement of the first means to the first position and operative in the second position to obtain a movement of the first means to the second position;

third means operative with the first and secondmeans in the first positions for simultaneously movingfithe first and second hubs in a direction to lock the second reel on the second hub; and

reels,

fourth means operative with the first and second means in the second position for moving the first hub in a direction to lock the first reel on the first hub.

20. In the combination set forth in claim 19, the first and second hubs being cylindrical and being rotatable and movable in an axial direction, the third means being responsive to the simultaneous movement of the first and second hubs in the axial direction to operate in a radial direction on the second reel for locking the second reel to the second hub, the fourth means being responsive to the movement ofthe first hub in the axial direction to operate in a radial direction on the first reel for locking the first reel to the first hub.

21. The combination set forth in claim 20 wherein the second means is engaged with the first hub in the first position of the first means and the second means and the second means is disengaged from the first hub in the second positions of the first means and the second means.

22. In apparatus for rotatably mounting two spaced reels, the combination of:

first and second axially aligned hub structures respectively to mount first and second ones of the spaced reels; first and second circumferential elastomeric rings respectively disposed on the first and second axially aligned hub structures;

first and second means respectively on the first and second hub structures, each of the first and second means being axially operable to compress the corresponding rings axially without changing the inside diameters of the rings thereby to cause the rings to bulge radially outwardly into engagement with the corresponding reels; and

means manually movable between first and second positions, the manual means being operable in the first position to provide an engagement between the first and second means for providing for a locking of the first reel on the first hub structure, the manual means being operative in the second position to disengage the second means from the first means for providing for a locking of the second reel on the second hub structure.

23. In the combination set forth in claim 22, the first and second means respectively including male and female detent means for providing an engagement between the first and second means and having means for urging the male detent means toward the female detent means and the manually operable means including means operatively coupled to the second hub structure for engaging the second hub structure in the first position of the manually operable means and for becoming disengaged from the second hub structure in the second position of the manually operable means.

24. Means to drive a reel, comprising:

a hub structure to mount the reel, said hub structure having a first second and a second section, said two sections cooperating to define an outer circumferential groove having parallel sidewalls normal to the axis of the hub structure, said sections being relatively movable axially for axial contraction and expansion of the circumferential groove;

an outer circumferential elastomeric ring in said groove having parallel flat faces to be bulged radially outwardly into engagement with the reel in response to axial compression of the ring by axial contraction of the groove; and

manually operable screw means in the screw-threaded engagement with one of said sections for screw action therewith to exert axial thrust on the other section to contract the groove, said first and second sections being slidingly keyed together to prevent relative motion therebetween when said screw is rotated, means on the hub structure to engage the reel to prevent relative rota tion between the reel and the hub structure prior to the engagement of the reel and the hub structure and prior to the engagement of the elastomeric ring with the reel whereby the reel may serve as manual means to prevent rotation of the hub structure when the screw means is operated. 

1. In an apparatus for driving two reels to control a ribbon of flexible material with one reel functioning as a takeup reel and the other reel functioning as a supply reel for moving the ribbon in one direction and vice versa, the combination of: two hub structures to mount the two reels respectively; two corresponding motors to drive the two hub structures respectively in one respect for use of one reel as a takeup reel and use of the other reel as a supply reel and in the opposite respect for use of the said one reel as a supply reel and said other reel as the takeup reel; two corresponding brakes; two corresponding one-way clutches operatively connecting the two hub structures respectively to the two brakes; each of said two one-way clutches being oriented to permit freewheeling of the corresponding reel when the corresponding reel is rotated in the direction to serve as a takeup reel; said two brakes being electrically actuated brakes and being released when energized and applied when deenerigized; and whereby with the two motors and the two brakes energized by a common EMF source, failure of the source with consequent deenergization of the two motors makes effective the brake of whichever hub structure is rotating its reel in the direction to serve as a supply reel.
 2. A combination as set forth in claim 1 in which the braking force of each of the two brakes is applied by spring means when the brake is deenergized and in which the spring means is adjustable to vary the braking force.
 3. In an apparatus for rotatably mounting two closely spaced coaxial reels, the combination of: closely spaced forward and rearward axially aligned hub structures to mount a forward reel and a rearward reel respectively; two outer circumferential elastomeric rings on the two hub structures respectively; screw means on the two hub structures respectively operable to compress the corresponding rings axially without changing the inside diameter of the rings thereby to cause the two rings to bulge radially outward into engagement with the corresponding reels; manual means having a first normal position at which it is operatively connected to the screw means of the forward hub structure; and said manual means being movable to a second position to releasably interconnect the forward hub structure and the screw means of the rearward hub structure thereby to permit the forward hub structure to serve as means to operate the screw means of the rearward hub structure, said manual means at its second position being operatively disconnected from the screw means of the forward hub structure.
 4. In an apparatus for rotatably mounting two closely spaced coaxial reels, the combination of: closely spaced forward and rearward axially aligned hub structures to mount a forward reel and a rearward reel respectively; two outer circumferential elastomeric rings on the two hub structures respectively; screw means on the two hub structures respectively to compress the corresponding rings axially to expand the rings into engagement with the corresponding reels; shoulder means on the rearward one of the two hub structures; connecting means disposed on the forward one of the two hub structures and movable between first and second positions and disposed in the first position out of register with the rearward hub structure and operative in the second position to engage the shoulder means of the rearward hub structure; manual means to operate the screw means of the forward hub structure; said screw means of the rearward hub structure having a forward end wall that blocks movement of said connecting means to its second position when the connecting means is out of register with said shoulder means; manually operable cocking means to place said connecting means under spring pressure to urge the connecting means to its second position; and whereby witH the connecting means out of register with the shoulder means, the cocking means may be operated to place the connecting means under spring pressure and the relative rotation may then be created between the forward hub structure and the screw means of the second hub structure until the connection means is registered with the shoulder means to permit the connecting means to snap into engagement with the shoulder means.
 5. A combination as set forth in claim 4 in which said shoulder means comprises a plurality of longitudinal bores in the forward end of the screw means of the rearward hub structure and said connecting means comprises a corresponding plurality of pins dimensioned to enter said bores.
 6. In an apparatus for rotatably mounting two closely spaced coaxial reels, the combination of: closely spaced forward and rearward axially aligned hub structures to mount a forward and a rearward reel respectively; said forward hub structure having a rear transverse wall with a first plurality of bores longitudinally therethrough; two outer circumferential elastomeric rings on the two hub structures respectively; screw means on the two hub structures respectively to compress the corresponding elastomeric rings axially to expand the elastomeric rings into engagement with the corresponding reels; and said screw means of the rearward hub structure having a second plurality of bores longitudinally thereof corresponding to the first plurality of bores to register therewith at a given rotary position of the forward hub structure relative to the screw means of the rearward hub structure; a plurality of pins mounted respectively in said first plurality of bores, each of said pins having a first flange means on its rearward end and second flange means intermediate between its two ends; an axially movable transverse means in the forward hub structure having a plurality of portions respectively adjacent said pin between the first and second flange means thereof; a plurality of coil springs respectively embracing said pins between said transverse means and said second flange means of the pins; said transverse means having a normal forward position against said first flange means of the pins to keep the pins retracted from the second plurality of holes and having an alternate rearward position compressing said coil springs against the second flange means of the pins to urge the pins into the second plurality of holes thereby to operatively connect the forward hub structure to the screw means of the rearward hub structure for operation of the screw means by the forward hub structure; manually rotatable means having a normal forward position for engagement with the screw means of the forward hub structure for rotation thereof and being movable to a rearward position against said transverse means to force the transverse means to its second position; and whereby when the forward hub structure is out of said given relative rotary position, said manually rotatable means may be moved to its second position to cause said transverse means to compress said coil springs and then the forward hub structure may be rotated to said given relative rotary position to cause the coil springs to snap the pins into the second plurality of bores.
 7. A combination as set forth in claim 6 in which said second flange means of the plurality of pins are positioned to cooperate with said transverse wall of the forward hub structure to limit the movement of the pins into the second plurality of holes.
 8. A combination as set forth in claim 6 which includes means to releasably latch said manually rotatable means at its second position.
 9. A combination as set forth in claim 6 which includes means to releasably latch said forward manually rotatable means at its second position in response to relatively small rotation of the manually rotatable means at its second position.
 10. In an assembly for mounting at an opening in a panel to drive two reelS on the forward side of the panel, the combination of: a housing for attachment to the panel in a position extending rearwardly of the panel in alignment with said opening; a pair of coaxial shafts comprising an inner axial shaft and an outer tubular shaft encompassed by the housing and extending both forwardly and rearwardly from the housing; a forward hub structure on the forward end of the axial shaft for mounting and driving a forward reel; two power means carried by the housing and operatively connected to the rear ends of said two shafts respectively to drive the two hub structures respectively; and said two hub structures being of less diameter than said opening whereby said housing may be detached from the panel to permit the assembly to be withdrawn rearwardly from the panel with said structures passing rearwardly through said opening in the panel.
 11. A combination as set forth in claim 10 which includes: retaining means extending across the rear end of said assembly; thrust bearing means effective between the rear ends of the two shafts and said housing; means to releasably anchor the retaining means to the housing thereby to cooperate with said thrust bearing means to maintain the two shafts in their assembled positions relative to the housing; and whereby the retaining means may be released and said hub assemblies may be removed from the front ends of the two shafts to permit the two shafts to be withdrawn forward from the housing.
 12. In apparatus for rotatably mounting two spaced reels, the combination of: a first shaft; a second shaft coaxial with the first shaft; a first hub mounted on the first shaft for engaging and driving a first one of the two spaced reels; a second hub mounted on the second shaft for engaging and driving a second one of the two spaced reels; control means having first and second positions and operative in the first position to engage the first hub for driving the first hub and operative in the second position to become disengaged from the first hub; and means operatively coupled to the first hub and responsive to the engagement of the first hub by the control means in the first position of the control means for operating upon the second hub to lock the second hub and the second reel.
 13. In the combination set forth in claim 12, means on the second hub for engaging the second reel during the action of locking the second hub and the second reel to prevent the second reel from being rotated relative to the second hub during such locking action.
 14. In the combination set forth in claim 12, means operatively coupled to the first hub and responsive to the operation of the control means in the second position for operating upon the first hub to lock the first hub and the first reel.
 15. In the combination set forth in claim 14, means on the first hub for engaging the first reel during the action of locking the first hub and the first reel to prevent the first reel from being rotated relative to the second hub during such locking action.
 16. In apparatus for rotatably mounting two spaced reels, the combination of: a first shaft; a second shaft coaxial with the first shaft; a first hub mounted on the first shaft for driving a first one of the two spaced reels; a second hub mounted on the second shaft for driving a second one of the two spaced reels; means operatively coupling the first and second hubs for synchronously operating the first and second hubs during the action of locking of the second reel on the second hub; and means operatively disengaging the first and second hubs for disengaging the second hub from the first hub during the action of locking the first reel on the first hub.
 17. In the combination set forth in claim 16, means on the second hub for engaging the second reel, during the action of locking the second hub on the second reel, to prevent the second hub from rotating relative to the second reel during such locking action.
 18. In the combination set forth in claim 17, means on the first hub for engaging the first reel, during the action of locking the first hub on the first reel, to prevent the first hub from rotating relative to the first reel during such locking action.
 19. In apparatus for rotatably mounting two spaced reels, the combination of: a first shaft; a second shaft coaxial with the first shaft; a first hub mounted on the first shaft for engaging and driving a first one of the two spaced reels; a second hub mounted on the second shaft for engaging and driving a second one of the two spaced reels; first means on the first hub and movable between first and second positions and extending to the second hub for engaging the second hub in the first position for movement of the second hub with the first hub and disposed in the second position in disengagement with the second hub; second means on the first hub and movable between first and second positions and operative in the first position on the first hub to obtain a movement of the first means to the first position and operative in the second position to obtain a movement of the first means to the second position; third means operative with the first and second means in the first positions for simultaneously moving the first and second hubs in a direction to lock the second reel on the second hub; and fourth means operative with the first and second means in the second position for moving the first hub in a direction to lock the first reel on the first hub.
 20. In the combination set forth in claim 19, the first and second hubs being cylindrical and being rotatable and movable in an axial direction, the third means being responsive to the simultaneous movement of the first and second hubs in the axial direction to operate in a radial direction on the second reel for locking the second reel to the second hub, the fourth means being responsive to the movement of the first hub in the axial direction to operate in a radial direction on the first reel for locking the first reel to the first hub.
 21. The combination set forth in claim 20 wherein the second means is engaged with the first hub in the first position of the first means and the second means and the second means is disengaged from the first hub in the second positions of the first means and the second means.
 22. In apparatus for rotatably mounting two spaced reels, the combination of: first and second axially aligned hub structures respectively to mount first and second ones of the spaced reels; first and second circumferential elastomeric rings respectively disposed on the first and second axially aligned hub structures; first and second means respectively on the first and second hub structures, each of the first and second means being axially operable to compress the corresponding rings axially without changing the inside diameters of the rings thereby to cause the rings to bulge radially outwardly into engagement with the corresponding reels; and means manually movable between first and second positions, the manual means being operable in the first position to provide an engagement between the first and second means for providing for a locking of the first reel on the first hub structure, the manual means being operative in the second position to disengage the second means from the first means for providing for a locking of the second reel on the second hub structure.
 23. In the combination set forth in claim 22, the first and second means respectively including male and female detent means for providing an engagement between the first and second means and having means for urging the male detent means toward the female detent means and the manually operable means including means operatively coupled to the second hub structure for engaging the second hub structure in the first position of the manually operable means and for becoming disengaged from the second huB structure in the second position of the manually operable means.
 24. Means to drive a reel, comprising: a hub structure to mount the reel, said hub structure having a first second and a second section, said two sections cooperating to define an outer circumferential groove having parallel sidewalls normal to the axis of the hub structure, said sections being relatively movable axially for axial contraction and expansion of the circumferential groove; an outer circumferential elastomeric ring in said groove having parallel flat faces to be bulged radially outwardly into engagement with the reel in response to axial compression of the ring by axial contraction of the groove; and manually operable screw means in the screw-threaded engagement with one of said sections for screw action therewith to exert axial thrust on the other section to contract the groove, said first and second sections being slidingly keyed together to prevent relative motion therebetween when said screw is rotated, means on the hub structure to engage the reel to prevent relative rotation between the reel and the hub structure prior to the engagement of the reel and the hub structure and prior to the engagement of the elastomeric ring with the reel whereby the reel may serve as manual means to prevent rotation of the hub structure when the screw means is operated. 